A "mammoth of research" is about to rise behind London's St Pancras station, a biomedical centre costing £600m and housing about 1,250 "cutting-edge" scientists. Ask not its value. Science jeers at the idea. The UK Centre for Medical Research and Innovation has already been dubbed a "cathedral of science", justified by faith, not reason.

In which context I turn to the Reith lectures. Each year the dear BBC gestures towards high seriousness by getting a celebrity intellectual to muse in public for four hours. Ennui is relieved with a chatty preamble from the redoubtable Sue Lawley, followed by safe, hand-picked questions and no nasty supplementaries. The whole thing has the air of a Soviet academy.

No one does it better than the astronomer and president of the Royal Society, Martin Rees, who concluded the 2010 series this week. Needless to say, he spoke to the BBC's current craze – anything to do with science. The airwaves are crammed with science quizzes, science chatshows, science magazines and science feedback. News must have science stories, the Today programme science items, all reverential. No scepticism is admitted to this new orthodoxy – or rather this revival of CP Snow's "two cultures" orthodoxy of the late 1950s.

Rees is shameless. After a brisk, familiar canter through the wonder of science – internet, genomes, bugs, space travel – his last lecture brought him to the matter in hand. Science, he said, should "engage broadly with society and public affairs". In other words, it should get more money. There is nowhere better to plead for this than on the BBC.

We are now shaping up for what, under the Osborne cuts, will be the greatest defensive operation in the history of Britain's professions. Rees will not allow scientists to miss out. He is rightly worried over public anxiety at the more disreputable antics of his colleagues. It was too bad that the Icelandic ash clouds turned out to be not as bad as "the science" had claimed. It was too bad if science banned beef on the bone; too bad if science wasted £2bn on Tamiflu; too bad if science wrecked the case for nuclear power by its hypersafe radiation limits, or failed properly to defend GM foods.

These, by implication, were the fault of politicians for taking science too literally. To Rees, "the advance of science spares us from irrational dread", and if science replaced irrational dread with an exaggerated fear of risk, that also is just too bad. Since science supplies its own "organised scepticism", its claims on the public purse should be asserted as infallible. Cathedrals are no place for question marks.

The Times ran a supplement before the election suggesting a "pro-science" MP was more important than any party, like "pro-life" candidates in America. To criticise science teaching is little short of blasphemy. Above all, science should be seen as above money. To Rees, a science grant is like an arts grant, a virtue beyond measure. In his lecture he insulted the financial sector as "not the real world", as "faffing around with derivatives" and as undeserving of any graduate's respect. (Yet within minutes Rees was moaning that in Britain there was not enough "venture capital for startups".)

The giveaway was a questioner who doubted the value of the Large Hadron Collider, on a par with aircraft carriers and Olympic games for useless extravagance. Rees stuck to the party line that forbids him to say that £7bn and "thousands of scientists" buried under a Swiss mountain might have been better employed on energy research. Politicians must show a sense of "priorities and perspectives", he said, but scientists do not do priorities. They just want money.

Rees is part of the lobby that led to the fiasco of the late 1980s, when colossal resources were devoted by the former Tory education secretary Lord Baker and others to maths and science education. They said it should form two thirds of the so-called core curriculum. Grants for science teaching soared. History and geography were demoted. University courses were expanded and colleges received twice as much grant for a science place as for an arts one.

By 1993, when the policy had been in place for a whole secondary school cohort, it had utterly failed. Demand for science GCSE and A-level had fallen by 10%. University science labs lay empty as entry requirements fell to E-grades. Yet a plummeting market for science graduates left government targets unchanged. A body called Save British Science castigated the "shocking underpayment" of scientists, even as it demanded that schools turn out ever more of them. It was a classic policy failure that passes unaudited, by government, by politics or by academia.

The science lobby reacted by turning itself into a religion. If economics could not justify its priority, then faith should do so. Men such as Rees and his colleague, Lord May, became archbishops preaching the word, that: "Britain needs more scientists." Their canticle was: "More money for research." Other vocational subjects such as law, accountancy and finance were deplored, even as the jobs market screamed for them. Unfashionable science-based occupations such as nursing and pharmacology had to burgle poor countries for staff.

Rees is two-faced about this talent theft. Facing the accusation that science steals bright graduates from poorer countries, he suggests that they should "fulfil their potential without emigrating", perhaps by Britain securing them "less dispiriting conditions" back home. He wants a collider in every kraal.

Yet he promotes just such theft. He wants more money or Britain's "success in attracting mobile talent will be at risk". Unless we continue to attract and nurture foreigners, we will "not retain international competitiveness". Less cash would jeopardise the nation's status in "the international premier league". It would damage Britain's "standing", its "leverage", indeed, the very "sustainability of its society".

This is big science, like big defence, dressing in the clothes of the League of Empire Loyalists. When a lobby is in full cry, no quarter is given to reason. If science is so international, why see it in such chauvinist terms? Why not let less-privileged countries share in the global talent? Besides, science is all on the internet.

A virtue of back-to-basics in public finance is that it might strip the cliches about "vital for the nation's interest" from the log-rolling. Every lobby is going into action to defend its subsidies. Scargill's miners were nothing to what we shall see from the scientists, doctors, lawyers, farmers, sportsmen and, above all, generals. They will turn on government as never before, claiming exemption from cuts in the cause of national pride and prosperity.

When pain is expected of every corner of the public sector, no claim to public money should escape scrutiny. Those intending to live off the earnings of others should always have to explain why.

I share Rees's glory in the wonder of science. I wish the wonder could be taught in schools, which still prefer to be kindergartens for lab technicians. But science research is one lobby among many. The BBC should not lavish it with favours against less-fashionable claimants for its platforms. One thing is for sure, Rees's subsidies must come from taxes on the professions he most despises – banking and finance. I bet no one devotes a research grant or a Reith lecture to them.